Rapid and quantitative major element analysis method for wet fine-grained sediments using an XRF microscanner
Rapid and quantitative major element analysis method for wet fine-grained sediments using an XRF microscanner
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DOI：
10.1016/j.margeo.2006.03.002
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发表时间：
2006-06-30
期刊：
影响因子：
2.9
通讯作者：
Tada, Ryuji
中科院分区：
文献类型：
--
作者：
Kido, Yoshiki;Koshikawa, Toshitada;Tada, Ryuji
为了满足湿沉积岩心高分辨率、快速、化学分析的要求，已开发了几种类型的X射线荧光岩心扫描仪。然而，由于很难评价沉积物表面水膜中的水和沉积物中间隙水的XRF吸收效果，特别是对较轻元素的XRF吸收效果，阻碍了它们在定量分析中的应用。在这项研究中，我们建立了一种利用XRF显微扫描仪对湿细颗粒沉积物样品进行无损、快速、高分辨率和定量的化学分析方法。实验结果表明，水膜对XRF的吸收程度与测量区域内沉积物的含水率呈明显的正相关。间隙水对XRF的吸收程度与测区以下沉积物的含水率之间也存在明显的正相关关系。用水含量与薄膜厚度的关系评价了薄膜对XRF的吸收，用含水率与间隙水的关系评价了间隙水对XRF的吸收。在测量XRF强度的同时，根据在同一测量区域测量的平均透射式X射线强度来估计测量区域下的水分含量。干样的主要元素Al、Si、K、Ca、Ti和Fe的当量XRF强度，即湿样品被薄水膜和间隙水吸收的XRF强度，与常规XRF方法测定的常量元素浓度具有较好的相关性。利用这种新方法，可以在6min内同时测量湿细颗粒沉积物上0.5×0.5 mm的面积内的平均水分和6种主要元素的平均浓度，比传统的XRF方法快近10倍。(C)2006爱思唯尔B.V.保留所有权利。
Several types of X-ray fluorescence (XRF) core scanners have been developed to fulfill the demands for high-resolution, rapid, chemical analysis of wet sediment cores. However, their application to quantitative analysis has been hampered by the difficulty of evaluating the XRF absorption effect of water in a water film on the sediment surface and interstitial water within the sediments, especially for lighter elements. In this study, we established a non-destructive, rapid, high-resolution, and quantitative chemical analysis method for wet fine-grained sediment samples using an XRF microscanner. Results of our experiments suggest that the degree of XRF absorption by the water film, which develops on the wet sample surface covered with Mylar film, shows a clear positive correlation with the water content of the sediments under the measurement area. A clear positive correlation also exists between the degree of XRF absorption by the interstitial water and the water content of the sediments under the measurement area. We evaluated the XRF absorption by the thin water film using the relationship between the water content and thickness of the thin water film, and the XRF absorption by the interstitial water using its relation with the water content. The water content under the measurement area is estimated from the average transmitted X-ray intensity that is measured on the same measurement area simultaneously with the measurement of XRF intensities. The dry sample equivalent XRF intensities of major elements (Al, Si, K, Ca, Ti, and Fe), which are the XRF intensities of wet samples corrected for the XRF absorption by the thin water film and the interstitial water show better correlation with the major element concentrations determined by conventional XRF methods. Using this new method, it is possible to measure the average water content and average concentrations of the 6 major elements simultaneously for a square area as small as 0.5 x 0.5 mm on the wet fine-grained sediment within 6 min, which is nearly ten times faster than the conventional XRF method. (c) 2006 Elsevier B.V All rights reserved.